Hydrogenation of oxygenated organic compounds



Patented June 9, 1936 UNITED STATES PATENT OFFICE HYDROGENATION F OXYGENATED ORGANIC COMPOUNDS John C. Woodhouse, Cragmere, DeL, assignor to E. I. du Pont de Nemours & Company,'Wilmington, Del., a corporation of Delaware No Drawing.

19 Claims.

the catalytic hydrogenation of carbon oxides under elevated temperatures and pressures. This application is a continuation in part of my cope'nding application Ser. No. 676,671, filed December 18, 1934.

In the catalytic hydrogenation of the oxides of carbon, there are obtained, under certain conditions of operation, mixtures of oxygen-containing organic compounds of a higher order than methanol which products, usually of an oily consistency, comprise chiefly the saturated alcohols with four or more carbon atoms, together with saturated and unsaturated compounds such as the aldehydes, ketones, esters, and the like. In the U. S. patent of E. F. Izard, No. 1,993,552, filed Feb. 14, 1933, the dibasic acid esters of a mixture of these compounds are disclosed together with a method for their preparation. The method is effected essentiallyby reacting a lower alkyl ester oi a polybasic organic carboxylic acid with the higher oxygenated organic compounds, ob-

iii

tained by the catalytic hydrogenation of carbon oxides under elevated temperatures and pressures, and in the presence of such catalysts as lead oxide. Esters of the above mixture oi. oxygenated organic compounds with the following polybasicacids are designated in that application: oxalic, malonic, succinic, phthallc, glutaric,

adipic, pimelic, suberic, hexahydrophthalic, seba- 35 ganic compounds usually of a somewhat oily consistency as prepared, is often colored and has an unpleasant odor. Consequently, the esters and other compounds prepared from this mixture of organic materials and which may be prepared by their interaction with acids or other compounds adapted to react therewith also have, due inter alia to more or less decomposition during esteriflcation, an unpleasant odor and are usually more highly colored. The lower alkyl esters of the above polybasic acids, such, for example; as the dimethyl, dibutyl, diamyl esters of those acids and more particularly such esters as the dialkyl phthalates are likewise often highly colored as prepared.

Esters of a similar character are preparedby the esteriflcation of octadecanedioi (which may be synthesized in accord with the disclosure in 56 cic, carbonic, tricarballylic, aconitic, phosphoric, 4 tartaric, etc. 'The mixture of oxygenated orthe Lazier and Werntz cope nding application Ser.

Application July 20, 1935, Serial No. 32,407

No. 619,734, filed June 28, 1932, which discloses a method of hydrogenating castor oil to octadecanediol) with the carboxylic acids giving, for example, diacetate, succinate, phthalate, diisobutyrate, hexahydrophthalate and adipate of 5 octadecanediol. In most instances these products as well as the glycol diacylates, such as di-ethylene glycol diisobutyrate, di-ethylene glycol dipropionate and the higher esters of the glycols and glycerine are likewise discolored when prepared and because of this discoloration their utility is limited. I

An object of the present invention is to provide a process for decolorizing and deodorizing by'hydrogenation oi oxygenated organic compounds containing two esterifled groups.

Another object of the invention is to provide a process for the hydrogenation of the products obtained by the interaction of the oxygenated organic compounds, obtained by the catalytic hydrogenation of carbon oxides under pressure, with other compounds adapted to react therewith. Yet another object of the invention is to provide a-process for the p'uriiication by hydrogenation of the products obtained by the interaction of the oxygenated organic compounds, obtained by the catalytic hydrogenation of carbon oxides under pressure, and the dicarbcxylic acids. A further object of the invention is to provide a process for the purific'ation and deodorization of the'compounds by catalytic hydrogenation under elevated temperature and pressure. Other objects and advantages will hereinafter appear.

I have found that the esters and other products obtained by the interaction of the oxygenated organic compounds, obtained by the catalytic hydrogenation of carbon oxides under pressure, with acids or other reactants adapted to react with them, can be rapidly and in a simple manner converted into substantially colorless and odorless products which do not discolor upon standing and which have only a slight and not particularly unpleasant odor. This conversion may be accom-. plished by hydrogenation in accord with my invention, and the product resulting therefrom consists substantially of a mixture of esters and other compounds which contain as a result of the hydrogenation substantially no unsaturated bodies.

The process is-likewise applicable to other compounds containing a di-ester grouping such, for example as octadecanediol diacetate, octadecanediol adipate, octadecanediol phthalate, octadecanediol succinate, octadecanediol diisobutyrate, octadecanediol hexahydrophthalate, di-ethylens 2 aoeaess glycol diisobutyrate and di-ethylene glycol dipropionate, and the dialkyl dicarboxylic acid esters, such, for example, as the dimethyl, dipropyl, diisobutyl, and diamyl phthalate, oxalate, succinate, adipate and the other esters of the hereinbefore mentioned dicarboxylic acids.

The hydrogenation is carried out in substantially the following manner: to the mixture of compounds or ester there is added a' suitable amount of a hydrogenating catalyst, such, for exampie, as a nickel catalyst, similar to that usuallowed to imbibe the nickel nitrate solution.

ally employed for hydrogenating processes, the resulting mixture is heated to a temperature within the range of approximately 100-150 C. and hydrogen is then forced into the liquid which has been disposed in a suitable pressure-sustaining vessel and the hydrogen circulated through the liquid which is maintained under pressure of from 200-3000 lbs. per sq in. or higher. The circulation of the hydrogen is continued until all or substantially all of the unsaturated bodies contained in the mixture of compounds have been substantially completely decolorized and deodorized; this usually requires from 4-20 hours according to the typeof compound being hydrogenated, the temperature, and the activity of the catalyst used. If desired reducing gases other than hydrogen may be used, such, for example, as carbon monoxide, carbon monoxide and water, ammonia, etc.

The catalysts to be used in the hydrogenation are those usually employed for this purpose, such, for example, as nickel, cobalt, copper, platinum, alone or in mixtures, with or without a support or activating admixture, or both.

The invention will be described in greater detail in connection with the following specific examples according to which my invention may be carried out in practice, but the invention is not limited to the examples.

Example I.250 grams of phthalates made, in accord with the process described in the Izard patent supra, i. e. by ester interchange between a low alkyl ester of phthalic acid and higher oxygenated organic compounds resulting from the methanol synthesis, and boiling from 133-150 C.,

were charged into a steel tube along with 13 grams of nickel on kieselguhr catalyst. The charge was subjected to 1200 pounds hydrogen pressure and the temperature raised to 120 C. Homogeneity of the reaction mass was maintained by shaking of the tube. Hydrogen absorption ceased after 3 hours time. The product was allowed to cool and filtered free of catalyst. It was found to be odorless and water-white whereas the material before hydrogenation had a sharp disagreeable odor and a deep yellow color.

Example II.--5260 parts by weight of phthalates made in accord with the process described in the Iz'ard application supra, i. e. by ester interchange between a low alkyl ester of phthalic acid and higher oxygenated organic compounds resulting from the methanol synthesis, and boiling in the range 150-160 C. were charged into an autoclave along with 250 parts by weight of nickel on kiesclguhr catalyst. This catalyst was similar to that described in Lazier application Ser. No. 620,296, and may be prepared by dissolving one mol. of nickel nitrate (290 grams) in the minimum quantity of water; 100 grams of kieselguhr is The mixture is dried, it necessary, pulverized and allowed to fall gradually into a well stirred solution containing 1.5 mols of sodium carbonate in liters of water maintained at a temperature of 70 C. The precipitate is well washed and dried, after which it is reduced with hydrogen 4 hours at a temperature of 400-450 C. The autoclave was subjected to 1500 pounds hydrogen pressure and the temperature was raised to 5 120-130 C. Agitation was provided by means of an internal high speed stirrer. -Hydrogen absorption ceased after four hours reaction period.

- The product was cooled and filtered free of catalyst. The material taken for reaction and a 1 brown color and a burnt odor. The product after hydrogenation was free of odor and almost waterwhite.

Example III.500 parts of crude octadecanediol diacetate after filtration were charged into an autoclave with 50 parts of nickel on kieselguhr catalyst and subjected to 2700 pounds per sq. in. hydrogen pressure at a temperature from 150 C. After about two hours a practically odorless waterwhite ester was obtained.

Example IV.-The conditions of Example III were duplicated with di-ethylene glycol diisobutyrate as the charge and a product of excellent clarity was realized.

Catalysts other than those indicated above may be used in my process; for example, the oxides of the metals of Group VI-A of the periodic table which may be used in conjunction with the nickel,

cobalt, and copper catalysts, resulting in such catalysts as nickel chromite, copper chromite, and the like.

Phthalic acid esters of various mixturesof the oxygenated organic compounds have been made. The mixtures of oxygenated organic compounds are obtained by fractionating the products obtained from the methanol synthesis to give, for example, several fractions having boiling ranges of 133-147; 147-157; 157-170; and 170 up; other fractions may, of course, be made. Phthalic acidesters made from the fraction boiling from 133-147" C. have a boiling range of 184-189 C., from the fraction boiling between 147-157 C. the phthalic ester boiling between 192-195 C., from the fraction 157-170 a phthalic ester boiling between 195-200 C., and from 170-190 an ester from 4.) 205-220 C. are obtained. A mixture of these esters boiling between approximately 184-220 C. may be obtained by esteritying a mixture of all fractions. The boiling points 01' the fractions are given at 760 mm. pressure, of the phthalic acid esters at approximately 5 mm. pressure.

From a consideration of the above specification it will be realized that any process for the purification by hydrogenation of the above designated compounds will come within the scope of I my invention without sacrificing any of its advantages.

I claim:

1. In a process for the removal of color and odor from an oxygenated organic compound which 69 contains at least two esterifled groups, the steps which comprise intimately dispersing a hydrogenating catalyst into the ester and subsequently reducing it by the infusion of a reducing agent under elevated pressure and a temperature of 100-150C.

2. In a hydrogenation process for the removal of color and odor from an omgenated organic compound which contains at least two esterified groups, the steps which comprise intimately dispersinga hydrogenation catalyst into the ester and subsequently hydrogenating it by the infusion of hydrogen under elevated pressure and a temperature of from to C.

3, Ina process for the removal of color and 75 odor from an oxygenated organic compound which contains at least two esterifled groups, the steps which comprise intimately dispersing from .05 to 5% of a hydrogenation catalyst into the ester, and subsequently hydrogenatlngit by the infusion of hydrogen under an elevated pressure and a temperature of 100-150 C.

4. In a process for the removal of color and odor from an oxygenated organic compound which contains at least two esterifled groups, the steps which comprise intimately dispersing a nickel hydrogenation catalyst into the ester and subsequently hydrogenating it at a temperature of 100-150 C. and under a partial pressure of hydrogen of from 200-3000 lbs. per square inch, unetiil the compound is decolorized and deodor- .z

5. In a process for the removal of color and odor from an oxygenated organic compound which contains at least two esterifled groups, the steps which comprise intimately dispersing approximately 1% of a nickel hydrogenation-catalyst into the ester and-subsequently hydrogenating it by the infusion of hydrogen at a temperature of from loo-150 C. and under a partial pressure of hydrogen of from 200-3000 lbs. per

, square inch.

6. In a hydrogenation process for the removal of color and odor from an oxygenated organic compound which contains at least two esteriiled groups, predominantly esters of the oxygenated organic compounds obtained from the catalytic hydrogenation of carbon oxides under elevated temperature and pressure, the steps which comprise lntlmately dispersing a hydrogenating catalyst into the esters and subsequently hydrogenating them by the infusion of hydrogen under elevated temperature and pressure.

7. In a hydrogenation processfor the removal of color and odor from an oxygenated organic compound which contains at least two esterifled hydrogenation of carbon oxides under elevated temperatures and pressures, the steps which comprise intimately dispersing a nickel hydrogenation catalyst into the esters and subsequently hydrogenating them at a temperature of 100-150" C. and under a partial pressure of hydrogen of from 200-3000 lbs. per square inch, until the compounds are decolorized and deodorlzed,

.9. In a hydrogenation process for the removal or color and odor from an oxygenated organic compound which contains at least two esterifled groups, predominantly esters of the oxygenated organic compounds obtained from the catalytic hydrogenation of carbon oxides under elevated temperatures and pressures, the steps which comprise intimately dispersing a nickel hydrogenation catalyst into the mixture and subsequently hydrogenating; and purifying it by the infusion of hydrogen under elevated temperature and pressure, the infusion being carried out under violent agitation and the pressure being maintained by forcing the hydrogen into the mixture under elevated pressure.

10. In a hydrogenation process for the removal of color and odor from an oxygenated organic a compound which contains at least two esterified groups, predominantly esters of the oxygenated organic compounds obtained from the catalytic hydrogenation of carbon oxides under elevated temperatures and pressures, the steps which com- In prise intimately dispersing approximately 1% of a nickel hydrogenation catalyst into the ester and subsequently hydrogenating them by the infusion of hydrogen at a temperature of from 100-150 (3., and under a partial pressure of hydrogen of 15 from 200-3000 lbs. per square inch.

11. In a hydrogenation process for the removal of color and odor from an oxygenated organic compound which contains at least two esteriiled groups, predominantly polybasic acid esters of 20 the oxygenated organic compounds obtained from the catalytic hydrogenation of carbon oxides under elevated temperatures and pressures, the steps which comprise intimately dispersing a hydrogenating catalyst into the mixture of esters and subsequently hydrogenating them by the infusion of hydrogen under elevated temperature and pressure.

12. In a hydrogenation process for the removal of color and odor from an oxygenated organic compound which contains at least two esterifled groups, predominantly esters of the oxygenated organic compounds resulting from the ester interchange between the oxygenated organic compounds obtained from the catalytic hydrogenation or carbon oxides under elevated temperatures and pressures and an alkyl ester of a polybasic acid, the steps which comprise intimately dispersing a hydrogenating catalyst into the mixture of esters and subsequently hydrogenating 4o them by the infusion of hydrogen under elevated temperature and pressure.

13. In a hydrogenation process for the removal of color and odor from the phthaiic acid esters of the oxygenated organic compounds obtained from the-catalytic hydrogenation of carbon oxides under elevated temperatures and pressures, the. steps which comprise intimately dispersing the hydrogenating catalyst into the esters and subsequently hydrogenating them by the infusion of hydrogen under elevated temperature and pressure.

14. In a hydrogenation process for the removal of color and odor from octadecanediol diacetate, the steps which comprise intimately dispersing approximately 1% of a nickel hydrogenation catalyst into the ester and subsequently hydrogenating it by the infusion of hydrogen at a temperature of from 100-150 C., and under a par tial pressure of hydrogen of from 200-3000 lbs.

per square inch.

15. In a hydrogenation process for the removal of color and odor from iii-ethylene glycol diisobutyrate, the steps which comprise intimately dispersing approximately 1% ofa nickel hydrogenation catalyst into the ester and subsequently hydrogenating it by the infusion of hydrogen at a temperature of from 100-150'" 0.. and under a partial pressure of hydrogen of from 200-3000 lbs. per square inch.

16. A new composition of matter.--a waterwhite mixture of saturated compounds. predominantly esters of the oxygenated organic compounds obtained from the catalytic synthesis of methanol from carbon monoxide and hydrogen 76 conducted under elevated temperatures and pressures, which compounds prior to esterification boiled above methanol.

1'7. A new composition of matter,a water- 7 white mixture of saturated compounds, predominantly esters of the oxygenated organic compounds obtained from the catalytic synthesis of methanol from carbon monoxide and hydrogen conducted under elevated temperatures and pressures, which compound prior to esterifleation had a boiling range of from approximately 184 C., to 220 C.

aogaeee JOHN C. WOODHOUSE. 

